(1) Field of the Invention
This invention relates to a steering shaft support device useful for a steering column assembly in which the steering shaft is required to be supported at two axially spaced positions as in rack and pinion type steering system.
(2) Description of the Prior Art
In the rack and pinion type steering system, radial loads are applied to the lower end of the steering shaft, so that it is necessary to support the steering shaft at two axially spaced positions.
On the other hand, a shock absorbing type steering system which is designed to absorb the collisional energy through the steering shaft is generally provided with a shear pin to permit contraction of the steering shaft in the axial direction in the event of a vehicle collision. The steering shaft, however, is also subjected to axial thrust loads from time to time other than on the occasion of vehicle collision or crash, so that it has to be fixed in the axial direction relative to and on opposed sides of the shear pin.
Therefore, in a rack and pinion type steering column assembly with an energy absorbing mechanism, it is necessary to support the steering shaft at two axially distant positions to provide support in both radial and axial directions.
However, axial dimensional errors of the column tube and steering shaft which occur during the manufacturing process make the fixation at two axial positions difficult or almost impossible due to misalignment of the fixing members on the steering shaft and column tube simultaneously at two different positions.